Project description:The decline of endothelial autophagy is closely related to vascular senescence and disease, although the molecular mechanisms connecting these outcomes in vascular endothelial cells (VECs) remain unclear. Here, we identify a crucial role for CD44, a multifunctional adhesion molecule, in controlling autophagy and aging in VECs. The CD44 intercellular domain (CD44ICD) negatively regulates autophagy by reducing PIK3R4 and PIK3C3 levels and disrupting STAT3-dependent PtdIns3K complexes. CD44 and its homologue clec-31 are increased in aging vascular endothelium and Caenorhabditis elegans, respectively, suggesting that an age-dependent increase in CD44 induces autophagy decline and aging phenotypes. Accordingly, CD44 knockdown ameliorates age-associated phenotypes in VECs. The endothelium-specific CD44ICD knock-in mouse is shorter-lived, with VECs exhibiting obvious premature aging characteristics associated with decreased basal autophagy. Autophagy activation suppresses the premature aging of human and mouse VECs overexpressing CD44ICD, function conserved in the CD44 homologue clec-31 in C. elegans. Our work describes a mechanism coordinated by CD44 function bridging autophagy decline and aging.
Project description:Aging of biological systems is controlled by various processes which have a potential impact on gene expression. Here we report a genome-wide transcriptome analysis of the fungal aging model Podospora anserina. Total RNA of three individuals of defined age were pooled and analyzed by SuperSAGE (serial analysis of gene expression). A bioinformatics analysis identified different molecular pathways to be affected during aging. While the abundance of transcripts linked to ribosomes and to the proteasome quality control system were found to decrease during aging, those associated with autophagy increase, suggesting that autophagy may act as a compensatory quality control pathway. Transcript profiles associated with the energy metabolism including mitochondrial functions were identified to fluctuate during aging. Comparison of wild-type transcripts, which are continuously down-regulated during aging, with those down-regulated in the long-lived, copper-uptake mutant grisea, validated the relevance of age-related changes in cellular copper metabolism. Overall, we (i) present a unique age-related data set of a longitudinal study of the experimental aging model P. anserina which represents a reference resource for future investigations in a variety of organisms, (ii) suggest autophagy to be a key quality control pathway that becomes active once other pathways fail, and (iii) present testable predictions for subsequent experimental investigations.
Project description:In this study, we investigated the impact of autophagy inhibition in cancer cell on the tumor immune microenvironment (TIME) of orthotopic syngeneic pancreatic ductal adenocarcinoma (PDAC) tumors. Dendritic cells (DCs) in the cancer cell autophagy inhibited tumors showed significantly higher expression of genes related to DC functions such as antigen-presentation, migration, IFN response, compared to control tumors. Our results indicate that autophagy inhibition in cancer cells induce the enhancement of adoptive tumor immunity via DC activation in PDAC.
Project description:Energy homeostasis plays a key role in retarding aging, and mitochondria are responsible for energy production.AMPK plays a central role in maintaining energy homeostasis and mitochondrial homeostasis, and commands autophagy, a clearing and recycling process to maintain cellular homeostasis. However, the effect of AMPK activators on kidney aging has not been fully elucidated. We testified the effects of O304, a novel direct AMPK activator, in naturally aging mice model and D-galactose (D-gal)-treated renal tubular cell culture. We identified that O304 perfectly protects against cellular senescence and aged-related fibrosis in kidneys. Also, O304 restored energy metabolism, promoted autophagy, and preserved mitochondrial homeostasis. Transcriptomic sequencing also proved that O304 induced fatty acid metabolism, mitochondrial biogenesis and ATP process, and downregulated cell aging, DNA damage response and collagen organization. All these results suggest that O304 has a strong potential to retard aged kidney injury through regulating AMPK-induced multiple pathways.
Project description:Transcriptomic analysis of macrophages harvested over the circadian day from young and aged mice reveals a loss of temporal synchrony in rhythmic gene expression with aging.
Project description:We explored how aging impacts transcriptional dynamics using single-cell RNA-sequencing to profile hundreds of CD4+ T cells from young and old mice from two divergent species. In young animals, immunological challenge drives a conserved transcriptomic switch from highly variable to tightly regulated gene expression, characterized by a strong up-regulation of a core activation program, coupled with a decrease in cell-to-cell variability. Aging significantly perturbed the activation of this core program, and increased expression heterogeneity across the population of cells in both species.